Disk brake for elevator drive

ABSTRACT

An elevator drive includes a casing with a shaft supported by spaced shaft bearings. Arranged on the shaft between the bearings are a traction sheave and a brake disk. On a free end of the shaft is a motor ventilated by fans. Arranged on the casing is a symmetrically constructed braking device with two single-arm brake levers having brake linings which, when braking occurs, press against the traction sheave and bring it to a standstill. Provided on a free end of each brake lever is a compression spring that is supported at one end on the brake lever and on the other end on a spring pin. The spring force of the compression spring acts on the brake lever thereby causing the brake lining to press against the traction sheave. To release the brake lever, a brake magnet provided with an armature plate is arranged on a brake lever, the brake magnet and the armature plate acting against the force of the compression springs.

BACKGROUND OF E INVENTION

[0001] The present invention relates to a disk brake for an elevatordrive, the brake having brake levers with brake linings, compressionsprings, and a brake magnet, the brake levers being caused by the forceof the compression springs to act through the brake linings on a brakedisk and bring the elevator drive to a standstill, and the brake leversbeing released by the brake magnet acting on the brake levers againstthe force of the compression springs.

[0002] The European patent specification EP 0 535 344 shows a disk brakethat acts on a brake disk of an elevator drive, the symmetricallyconstructed disk brake thereby bringing the elevator drive to astandstill. Two brake levers are pivoted on a rigid supporting bracket.Each brake lever has two arms, there being arranged at one end of thebrake lever a brake shoe with a brake lining that acts on the brake diskwhen braking occurs. Acting on the other end of the brake lever is acompression spring that is supported on a stop and on the brake lever.The compression spring of the second brake lever is also supported onthe stop, the stop being movably held in a brake magnet. If the stopmoves due to, for example, breakage of a compression spring, a sensorgenerates an alarm signal. To release the disk brake, the brake magnet,which is fitted with an armature plate, is activated, the brake magnetwith the armature plate thereby acting against the force of thecompression springs.

[0003] A disadvantage of this known device is that the disk brake withits centrally arranged brake magnets is of relatively wide constructionand therefore not suitable for situations where space is restricted.

SUMMARY OF THE INVENTION

[0004] The present invention provides a solution to avoiding thedisadvantages of the above-described known device and creating anelevator drive with a disk brake of narrow construction which can alsobe easily released manually.

[0005] The advantages achieved by the present invention are that theelevator drive can be constructed in modular manner. The elements of thesymmetrically constructed brake device are arranged outside the motorarea. The motor is therefore easily accessible and easily replaceable.The elements of the brake device are simply constructed and inexpensiveto manufacture. The brake device is redundant, and also functions withone brake lever. The single-arm brake levers permit the structure of theelevator drive to be shorter. Furthermore, the brake device can beremotely operated by hand by means of, for example, a Bowden cable. Theelements of the brake device are well accessible and easily replaceable.For disassembly it is only necessary to remove the compression springs.The brake device can then be removed upwardly. Maintenance (checking thebrake linings, the air gap of the magnet, the parallelism between thebrake magnet and armature plate, and the spring pretensioning) issimplified by the brake device according to the present invention.Because the brake device acts directly on the traction sheave, the brakedevice can be used as a protective device against overspeed of theelevator car in the upward direction.

DESCRIPTION OF THE DRAWINGS

[0006] The above, as well as other advantages of the present invention,will become readily apparent to those skilled in the art from thefollowing detailed description of a preferred embodiment when consideredin the light of the accompanying drawings in which:

[0007]FIG. 1 is a cross-sectional view taken along the line A-A in FIG.2 through an elevator drive with the brake device according to thepresent invention;

[0008]FIG. 2 is a top plan view of an elevator drive with the brakedevice according to the present invention;

[0009]FIG. 3 is a side elevation view of the elevator drive with thebrake device shown in FIG. 2;

[0010]FIG. 4 is a perspective view of cam levers for the manual remoteoperation of the brake device according to the present invention;

[0011]FIG. 5 is a perspective view of the brake device according to thepresent invention; and

[0012]FIG. 6 is a cross-sectional view through the brake magnet formagnetic remote operation of the brake device shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] FIGS. 1-3 show an elevator drive 1 including a casing 2 with abase 2.1, which serves as a damping element, and an endplate 2.2.Supported by bearings 4 in the casing 2 and the endplate 2.2 is a shaft3, a part of the shaft projecting from the casing as a free end.Arranged on the shaft 3 in between the shaft bearings 4 are a tractionsheave 5 and a brake disk 6. Passing over the traction sheave 5 and adeflection pulley 5.1 Rig. 3) are ropes (not shown) which drive and holdan elevator car (not shown) and a counterweight (not shown). Arranged atthe free end of the shaft 3 is a motor 7 with stator 7.1 and rotor 7.2,ventilation of the motor 7 being possible by means of fans 8. Providedat the motor end of the shaft 3 is a revolution sensor 10. The brakedisk 6 is provided to bring the shaft 3, and thereby the traction sheave5, to rest.

[0014] Arranged on the casing 2 is a symmetrically constructed brakedevice 11 that is protected by a cover 2.3. Pivoted on the casing 2 bypins 12 are two single-arm brake levers 13 with brake linings 14 which,when braking occurs, press against the traction sheave 5 to bring it toa standstill. The pins 12 serve as fulcrums for the brake levers 13. Atthe free end of each of the brake levers 13 is a spring pin 15 thatpasses through the brake lever and is arranged on the casing 2. Thespring pin 15 serves as a guide for a compression spring 16 that restsat one end against the brake lever 13 and at the other end against thespring pin 15. The spring force of the compression spring 16 acts on thebrake lever 13, thereby causing the brake lining 14 to press against thetraction sheave 5. To release the brake lever 13, there is arranged onthe brake lever 13 a brake magnet 17 with an armature plate 18, thebrake magnet 17 and the armature plate 18 acting against the force ofthe compression springs 16.

[0015] The brake device 11 can be remotely manually operated with littleforce, for example from the landing by means of a Bowden cable. For thispurpose, on the elevator drive 1, two cam levers 19 are provided at theend of the brake levers 13 to act against the force of the compressionsprings 16 on the brake levers and release the brake levers.

[0016] A pin 20 arranged on the casing 2 serves as fulcrum for the twocam levers 19. Arranged at the free end of the cam lever 19 is a pin 21on which, for example, the Bowden cable acts and moves the pins 21toward each other. In doing so, a cam 22 of the cam lever 19 actsagainst the force of the compression spring 16 on a contact surface 28(FIG. 5) of the brake lever 13 and the brake linings 14 are releasedfrom the brake disk 6. To monitor the position of the brake lever 13there is, for example, a microswitch 23 on each brake lever.

[0017] The cam levers 19 with the cams 22 are shown in more detail inFIG. 4 as arranged on the common fulcrum pin 20 to act as forcemultipliers between the Bowden cable and the compression springs 16. Asmall force on the Bowden cable can oppose the large force of thecompression springs 16. The manual remote operation with forcemultiplication can also be used, for example, on brake devices withdouble-arm brake levers.

[0018]FIG. 5 shows the brake device 11 without the cam levers 19. Twoindependent brake halves each comprise a brake lever 13 with the brakelining 14, the pin 12, the compression spring 16, the spring pin 15arranged on the casing 2, and an adjusting screw 24. Not shown in FIG. 5is the casing part 2 on which the spring pins 15 are arranged, andagainst which the adjusting screws 24 rest. To release the brake lining14, the brake magnet 17 acts together with the armature plate 18according to the action/reaction principle simultaneously on the twobrake levers 13. To prevent only one of the brake levers 13 fromopening, the movement of each brake lever is limited and adjustable bymeans of the adjusting screw 24.

[0019]FIG. 6 shows a section through the brake magnet 17 and thearmature plate 18. The brake magnet 17 is arranged on one of the brakelevers 13. The armature plate 18 is movable relative to the brake magnet17. By means of a magnetic force generated by a coil 25, which can beremotely electrically operated by the elevator control, the armatureplate 18 is moved toward the brake magnet 17. A plunger 26 arranged onthe armature plate 18 passes through the brake magnet 17 and the one ofthe brake levers 13 and ends in the other one of the brake leversconnected to a sliding bearing 26.1. The bearing 26.1 is coupled to anadjusting screw 27 that is joined to the other one of the brake levers13. The adjusting screw 27 can be rotated to limit the travel of thearmature plate 18. The parallelism between the brake magnet 17 and thearmature plate 18 can be set by means of an adjusting device 17.1comprising a bolt, a nut, and a rubber element. The adjusting device17.1 is connected between the one brake lever 13 and the brake magnet17. in accordance with the provisions of the patent statutes, thepresent invention has been described in what is considered to representits preferred embodiment. However, it should be noted that the inventioncan be practiced otherwise than as specifically illustrated anddescribed without departing from its spirit or scope.

What is claimed is:
 1. A disk brake for an elevator drive having atraction sheave connected to a brake disk, the disk brake comprising: apair of brake levers each having a fulcrum end for pivotal mounting anda free end; a pair of brake linings, each said brake lining beingattached to an associated one of said brake levers between said fulcrumend and said free end; a pair of compression springs, each saidcompression spring acting upon an associated one of said brake leversbetween said brake lining and said free end; and a brake release meansacting on said brake levers whereby when said the brake levers arepivotally mounted on a casing of an elevator drive on opposite sides ofa brake disk of the elevator drive with said fulcrum ends adjacent oneanother said brake linings adjacent opposite surfaces of the brake disk,said compression springs force said brake linings into engagement withthe brake disk to prevent rotation of a connected traction sheave tobring the elevator drive to a standstill, and said brake levers beingreleased by selective actuation of said brake release means acting onsaid brake levers against a force of said compression springs.
 2. Thedisk brake according to claim I wherein said brake release means is oneof a remotely operated manual means and a remotely operated magneticmeans.
 3. The disk brake according to claim 2 wherein said brake releasemeans includes a brake magnet with an armature plate, said brake magnetbeing mounted on one of said lever arms and said armature plate beingcoupled to another of said lever arms, whereby when said brake magnet isactuated, said armature plate is attracted to said brake magnet againstthe force of said compression springs to move said brake levers towardthe opposite surfaces of the brake disk.
 4. The disk brake according toclaim 3 including a plunger connected between said armature plate andsaid another brake lever.
 5. The disk brake according to claim 4 whereinsaid plunger extends through said brake magnet and said one brake leverand terminates in said another brake lever, and including an adjustingscrew in said another brake lever coupled to said plunger for limitingtravel of said plunger.
 6. The disk brake according to claim 3 includingan adjusting device connected between said brake magnet and said onebrake lever for setting parallelism between said brake magnet and saidarmature plate.
 7. The disk brake according claim I wherein said brakerelease means includes a pair of manually remotely actuatable cam leversmovable about a fulcrum point, each of said cam levers being engagablewith an associated one of said brake levers to move said brake leversagainst the force of said compression springs.
 8. The disk brakeaccording to claim 7 wherein each said cam lever has a cam formedthereon for engaging a contact surface formed on an associated one ofsaid brake levers.
 9. The disk brake according to claim 8 wherein eachsaid cam lever has a pin for connecting to a Bowden cable.
 10. Anelevator drive having a disk brake comprising: a casing rotatablymounting a shaft to which is attached a traction sheave and a diskbrake; a pair of brake levers each having a fulcrum end pivotallymounted on said casing and a free end, said brake levers extending onopposite sides of said brake disk and each having a brake liningattached between said fulcrum end and said free end; a pair ofcompression springs, each said compression spring acting upon anassociated one of said brake levers between said brake lining and saidfree end; and a brake release means acting on said brake levers wherebysaid compression springs force said brake linings into engagement withsaid brake disk to prevent rotation of said traction sheave to bring theelevator drive to a standstill, and said brake levers being released byselective actuation of said brake release means acting on said brakelevers against a force of said compression springs.
 11. The disk brakeaccording to claim 10 wherein said brake release means is one of aremotely operated manual means and a remotely operated magnetic means.12. The disk brake according to claim 11 wherein said brake releasemeans includes a brake magnet with an armature plate, said brake magnetbeing mounted on one of said lever arms and said armature plate beingcoupled to another of said lever arms, whereby when said brake magnet isactuated, said armature plate is attracted to said brake magnet againstthe force of said compression springs to move said brake levers towardthe opposite surfaces of the brake disk.
 13. The disk brake according toclaim 12 including a plunger connected between said armature plate andsaid another brake lever, said plunger extending through said brakemagnet and said one brake lever and terminating in said another brakelever, and including an adjusting screw in said another brake levercoupled to said plunger for limiting travel of said plunger.
 14. Thedisk brake according to claim 12 including an adjusting device connectedbetween said brake magnet and said one brake lever for settingparallelism between said brake magnet and said armature plate.
 15. Thedisk brake according claim 10 wherein said brake release means includesa pair of manually remotely actuatable cam levers movable about afulcrum point on said casing, each of said cam levers being engagablewith an associated one of said brake levers to move said brake leversagainst the force of said compression springs.
 16. The disk brakeaccording to claim 15 wherein each said cam lever has a cam formedthereon for engaging a contact surface formed on an associated one ofsaid brake levers.
 17. The disk brake according to claim 16 wherein eachsaid cam lever has a pin for connecting to a Bowden cable.